Promoting Health

Movement My Way

Examining Physical Activity in Children

movementChildhood obesity in the United States has tripled in the past 20 years, now affecting 12.5 million children between 2 and 19 years of age (Centers for Disease Control, 2011). Obesity presents serious problems to children’s health and puts them on a trajectory of health risks. Yet children’s obesity can in many cases be prevented. In fact, obesity is only determined 20 percent by genetics, with the other 80 percent being caused by poor nutrition, excessive calories, and inadequate physical activity.

One obvious but poorly understood entrée into addressing children’s obesity is to encourage physical activity. Two UNC faculty members in sports and exercise science, Dr. Megan Stellino and Dr. Christina Sinclair, have spent the past eight years conducting research with children to determine predictors of physical activity that may ultimately help prevent childhood obesity.

“The bottom line of our research is identifying the factors that help children choose to be active during their own free, discretionary time, which is the key to a lifetime of activity,” Dr. Sinclair said. The investigators and student collaborators began their research by observing children during recess because children generally are allowed to direct their own activities during this school period.

Observations of children’s behavior revealed important group differences. “We found that girls took fewer steps than boys, older children were more active than younger children, and children with an obese body mass index (BMI) took fewer steps and engaged in lower intensity activities,” said Dr. Stellino, sharing some of their findings from these initial observations. The researchers learned that girls were more motivated by competence — wanting to engage in physical activities they were good at while boys were more motivated by engaging in their choice of activity.

The researchers also asked children to draw themselves as they acted during free time. Children varied in the themes they included in their artwork, with some children relating their free time to competition and others focusing on peer interaction. These and other distinctions in themes, which reflect on children’s underlying motivations during free time, have implications for interventions. Programs designed to foster physical activity need to appeal to the full range of motivations that children pursue in their play, exercise, and personal initiative.

The researchers’ focus on motivation led them to interpret children’s actions in terms of children’s self- determination, the strong drive that youngsters have to make their own choices. Aggregating across their multiple studies, Drs. Stellino and Sinclair have found that children’s self-determination is associated with a range of factors, including children’s need to feel competent, autonomous, and connected with other people. “We are mapping on to self-determination; anyone would be more regulated in their activities if their distinct psychological needs are met,” Dr. Sinclair explained. “An example would be that boys’ need for autonomy predicted their need for more physical activity.”

Most existing programs for overweight children are highly regimented and fitness-based, not getting to the core issue of children’s motivations to engage in physical activity. “The problem with the current programs is that they are too structured — it is our antithesis. The essence of our research is about the children and their-well being,” Dr. Stellino said.

Both researchers said that overweight youth usually want to be more active on their own if they find something that they are good at.

health4What, then, can teachers and parents do to help children be more active? The research team emphasize the importance of allowing access and opportunity for children to explore and engage in physical activities in which they perceive themselves as skilled. Additionally, children need developmentally appropriate equipment, which can be as simple as having jump ropes of certain sizes that are aligned to children’s height. More importantly, Dr. Sinclair and Dr. Stellino assert that physical activity should be a priority during the school day. Teachers should avoid taking away recess as punishment; some children are motivated to stay inside with their teacher during recess instead of engaging in physical activities with their peers. Recess is as important to a child’s school day as mathematics instruction because it encourages healthy child development.

The next step for the research team is to investigate social predictors of physical activity in order to determine the roles that parents, teachers, and other individuals have on this important aspect of children’s health. Dr. Sinclair and Dr. Stellino are continually collecting data and determining their implications for intervention strategies that they hope will foster children’s decisions to engage in healthful levels of physical activity and good habits for a lifetime.